The term 'block of wood' can be described by two crossword solutions: 'CHOCK' (5 letters) and 'CLOG' (4 letters). CHOCK is a noun that refers to a wedge or block used to secure an object in place, such as a wheel or a door. CLOG is a verb that means to obstruct or fill up a passage with an obstacle, such as a block of wood. Therefore, a block of wood can be used as a CHOCK to secure an object in place, or it can be used to CLOG a passage and create an obstacle.